people
what was Neil Bohr known for?
electrons .
what is matter?
matter is anything that has a volume and mass.
what is an element?
A element consists of only one kind of atom.
what is the three things a fire needs to survive?
fuel, oxygen, and ignition
Lithium is a metal that is shiny and malleable. Is this description physical or chemical properties?
what did John Dalton do ?
he gave us the atomic theory .
what is an atom?
it makes up everything
what are evidence of chemical changes?
bubbles, new smells, color changes, temperature changes, and light emissions.
who made the three laws of thermodynamics?
Rudolf Clausius and William Thomson
One of the methods of separating a mixture is distillation. What separates liquids in a distillation?
boiling point
what did J.J Thomson discover?
the electron .
winter , spring , summer , and fall are all examples of ?
different types of seasons .
Which of the following are in the nucleus ?
a. protons
b . electrons
c. protons and neutrons
d. none of the above
answer choice c , protons and neutrons .
When heating a solution, a scientist detects a temperature increase in the solution during a period of time. Which of the following statements accurately characterizes the solution during this period?
The velocity of molecules in the solution is increasing.
This group of nonmetals is nonreactive.
noble gasses
what did Ernest Rutherford use to discover things about an atom ?
gold foil .
how do you know when something is more dense ?
density is determined by an objects mass and volume . if two objects take up the same volume but one has more mass then it also has a higher density . if a object is more dense then it will sink .
Which combination below corresponds to a cation with a +1 charge?
a. 7 protons and 8 electrons
b. 11 protons and 10 electrons
c. 18 protons and 18 electrons
d. 17 protons and 18 electrons
e. 20 protons and 18 electrons
answer b
what direction would heat flow if you put a cup of hot coffee in your hand?
from the coffee cup to your hand.
An iron nail is suspended on a thin wire in a sealed jar of moist air. The surface of the nail becomes red over time. What chemical change has occurred?
oxidation
who used the cathode ray tube in their discovery ?
J.J Thomson
which of the following terms refers to the number of molecules or ions attached to a central metallic atom ?
a. coordination number
b. connection number
c. bonding number
d. none of the above
coordination number
What is the molecular mass of Sulfur dioxide (SO2)?
64 g
According to the kinetic theory of gases, the average kinetic energy of the gas particles in a gas sample is directly proportional to the ?
temperature
66.7 mL of 18.0 molar sulfuric acid solution was dissolved in enough water to make 500 mL of solution. The molarity of the diluted mixture is
2.40 molar